The invention relates to a joining apparatus between a transportation container and a horizontal wall of a discharge enclosure which can in particular be used for effecting the discharge of lead containers into which have been loaded irradiated nuclear fuel elements after combustion in nuclear reactors. This apparatus can in particular be used for the dry transfer of fuel elements or nuclear waste to a reprocessing plant.
Irradiated fuel elements are generally discharged from such containers by the wet route using the process known under the name "pond discharge". This process makes it possible to solve in a relatively satisfactory manner certain of the radioactive contamination problems liable to occur during unloading operations. However, it has a certain number of disadvantages. Thus, it involves a complex succession of operations, part of which being inherent in the use of the wet route. This is particularly the case with regard to the operations of fitting and removing the protective skirts with which the containers must be covered when it is in the pond, as well as rinsing operations with water under high pressure aand decontamination operations effected by manual wiping of the wet parts. Pond discharge also involves the use of a large amount of equipment, such as the actual ponds and their accessory equipment, the protective skirts and a very extensive pipe system whose cumulative contamination causes problems. Due to the number and complexity of the operations and the large volume of equipment the known wet route processes require a considerable installation area. All these factors make the struggle against the spreading of radioactive contamination more difficult and more complex and thus tend to cancel out to a certain extent the advantages expected in this field from wet route processes.
Moreover pond discharge involves high manpower costs and the putting out of operation of the container for a very long period. The latter obviously has an unfavourable effect on the economic balance of the discharge process, because lead containers used for nuclear fuels are extremely costly and involve high investment expenditure. Moreover these very high manpower and immobilisation costs are subject to fluctuations because the duration of certain operations varies greatly as a function of the state of the products to be processed. These fluctuations are extremely disadvantageous with respect to the establishment and adherence to a rational operating programme.
These disadvantages which have been established during long-term experience with wet route processes have led to research being carried out on dry route discharge solutions which make it possible to significantly simplify the operating process and to greatly reduce investment costs, but which have been previously avoided through the absence of means making it possible to confine the radioactive contamination.